海工建造規(guī)范（DNV建造標(biāo)準(zhǔn)）

DNV-OS-C401”FabricationandTestingof

OffshoreStructures”JonR.Hansen2007.04.16DNV-OS-C401”FabricationandTestingofOffshoreStructuresVersionSlide211May2023ArneSmedal,DirectorSevanandNiTao,GeneralManagerCoscoNantongShipyardsigningthecontract.

DNV-OS-C401”FabricationandTestingofOffshoreStructuresVersionSlide311May2023StartingleftNorwegianConsul(Shanghai)FredH.Nomme,ArneSmedalandCoscoShipyardGroupPresidentWangXingRu.

DNV-OS-C401”FabricationandTestingofOffshoreStructuresThisiswhat’sallaboutVersionSlide411May2023DNV-OS-C401”FabricationandTestingofOffshoreStructuresCoursePurpose.TogiveabriefoverviewofDNVoffshorestandards.TogivebasicknowledgeoffabricationstandardOSC-401VersionSlide511May2023DNV-OS-C401”FabricationandTestingofOffshoreStructuresDNV’sROLEINOFFSHORECLASSIFICATIONDETNORSKEVERITAS(DNV)isanautonomousandindependentfoundationwiththeobjectivesofsafeguardinglife,propertyandtheenvironment,atseaandonshore.DNVundertakesclassification,certification,andotherverificationandconsultancyservicesrelatingtoqualityofships,offshoreunitsandinstallations,andonshoreindustriesworldwide,andcarriesoutresearchinrelationtothesefunctions.VersionSlide611May2023DNV-OS-C401”FabricationandTestingofOffshoreStructuresDNVOffshoreCodesconsistofathreelevelhierarchyofdocuments:VersionSlide711May2023ServiceSpecificationsOffshoreStandardsRecommendedPracticesDesignConstructionOperationInternationallyrecognisedcodesServiceSpecificationsVersionSlide811May2023ClassificationSafety,Health&EnvironmentDNV-OS-C401”FabricationandTestingofOffshoreStructures”Qualification&InnovationVerification&ClassificationAssetOperationShelfStateComplianceVerificationDNV-OS-C401”FabricationandTestingofOffshoreStructuresOffshoreServiceSpecifications.ProvideprinciplesandproceduresofDNVclassification,certification,verificationandconsultancyservices.VersionSlide911May2023OffshoreStandardsVersionSlide1011May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”A:QualityandSafetyMethodologyB:MaterialsTechnologyC:StructuresD:SystemsE:SpecialFacilitiesF:PipelinesandRisersABCDEFDNV-OS-C401”FabricationandTestingofOffshoreStructuresOffshoreStandards.ProvidetechnicalprovisionsandacceptancecriteriaforgeneralusebytheoffshoreindustryaswellasthetechnicalbasisforDNVoffshoreservices.VersionSlide1111May2023RecommendedPracticesVersionSlide1211May2023A:QualityandSafetyMethodologyB:MaterialsTechnologyC:StructuresD:SystemsE:SpecialFacilitiesF:PipelinesandRisersABCDEFGG:AssetOperationDNV-OS-C401”FabricationandTestingofOffshoreStructuresDNV-OS-C401”FabricationandTestingofOffshoreStructuresRecommendedPractices.

ProvideproventechnologyandsoundengineeringpracticeaswellasguidanceforthehigherlevelOffshoreServiceSpecificationsandOffshoreStandards.VersionSlide1311May2023DNV-OS-C401”FabricationandTestingofOffshoreStructuresDNVOffshoreCodesareofferedwithinthefollowingareas:A)Qualification,QualityandSafetyMethodologyB)MaterialsTechnologyC)StructuresD)SystemsE)SpecialFacilitiesF)PipelinesandRisersG)AssetOperationH)MarineOperationsVersionSlide1411May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”DifferenceShipRulesversusOffshorerulesRulesforOffshoreprojectsareinsomeareasquitedifferentfromthetraditionalShipRules,duetolongtimeonlocationwithnoorlimitedpossibilitiesleavethelocation.(>20–25yearsservicetime)VersionSlide1511May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Someimportantaspects:Structuralintegrityandstrength(Loadsbasedonenvironmentalconditionsonactuallocation)AccidentalloadstobeincludedinDesignLoads(DAL)Fatigue(attentiontodetails)MaintenanceCorrosionprotectionInserviceinspection(Accessetc.shouldbeplannedandprovidedduringnewbuildingphase)IncreasedreliabilityofMarinesystems,utilitysystemsandequipment.Safetysystems(Fire,explosion,abandoninstallationetc.)ShelfstaterequirementstoaccommodationandworkingenvironmentVersionSlide1611May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”DNV-OS-C401”FabricationandTestingofOffshoreStructures”CH.1INTRODUCTIONCH.2TECHNICALPROVISIONSCH.3CERTIFICATIONANDCLASSIFICATIONVersionSlide1711May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”

VersionSlide1811May2023CH.1INTRODUCTIONA200Objective201Theobjectivesofthisstandardareto:Provideaninternationallyacceptablestandardtoensurethequalityofallweldingoperationsusedinoffshorefabrication,throughidentifyingappropriateweldingprocedures,welderqualificationsandtestmethods.Serveasatechnicalreferencedocumentincontractualmattersbetweenpurchaserandcontractor.Serveasguidelinefordesigner,purchaserandcontractorSpecifyminimumrequirementsforweldingoperationssubjecttoDNVcertificationandclassification.DNV-OS-C401”FabricationandTestingofOffshoreStructures”Chapter2TechnicalprovisionsSec.1WeldingProceduresandQualificationofWeldersSec.2FabricationandTolerancesSec.3Non-DestructiveTestingSec.4OtherTestsSec.5CorrosionProtectionSystemsSec.6Miscellaneous

VersionSlide1911May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”

VersionSlide2011May2023Sec.1WeldingProceduresandQualificationofWeldersWeldingproceduresPre-WeldingProcedureSpecificationtoobepreparedandacceptedbypurchaser.WPQTtobebasedonacceptedPre-WPSWPSmaybebasedonpurchaseracceptedWPQTandinconformancewithanagreedqualificationscheme.WPSshallreflectconditionsandequipmentusedfortheactualproductionwelding.WPSshallreflecttheworkingenvironmentfortheworkshoporsitewheretheproductionweldingwillbeperformed.SpecificrequirementstoWPQTforC-MnsteelsarefoundinOS-C401Ch.2,Sec.1,C.DNV-OS-C401”FabricationandTestingofOffshoreStructures”AWPScanbeestablishedbyoneofthefollowingmethods:Performingofweldingproceduretest(WPQT)andsubsequentreviewoftheweldingprocedurequalificationrecords(WPQR)Reviewofpreviouslyqualifiedweldingprocedurestests(WPQT)whichhasbeenwitnessedbyapartyrecognizedbythepurchaserReviewofWPSReviewandverificationofdocumentationshowingsuccessfulapplicationofweldingproceduresoveraprolongedperiodoftime.VersionSlide2111May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”

VersionSlide2211May2023WeldersqualificationWelderswhoareweldinginmanualorpartlymechanizedweldingprocessesshallbequalifiedinaccordancewitharecognizedstandard(E.g.EN287,ISO9609,ASMEIXorANSI/AWSD1.1)Weldersusingfullymechanizedweldingorautomaticweldingprocesses,needgenerallynotpassaqualificationtest,butshallreceiveadequatetrainingforsettingandoperationofequipment.DNV-OS-C401”FabricationandTestingofOffshoreStructures”

VersionSlide2311May2023Sec.2.Fabricationandtolerances.FabricationPlanningAsaprerequisiteforfabrication,procedures,inspectionandtestplansandworkinstructionsforexecutionandcontroloffabricationactivitiesshallbeestablished.ContractorsinvolvedinfabricationofstructuralmembersshallhaveadocumentedandimplementedqualitysystemaccordingtoISO9001orequivalent.Workmanshipshallbeinaccordancewithwrittenproceduresacceptedbythepurchaser.Allworkshallbeexecutedwithadequatecontrolbythecontractor.Repairworkshallbecarriedoutinaccordancewithwrittenproceduresacceptedbythepurchaser.DNV-OS-C401”FabricationandTestingofOffshoreStructures”Faultsanddeficienciesshallbecorrectedbeforepaintingorothermeansofpermanentcovershavebeenapplied.PriortocommencementoftheworkthecontractorshallsubmitaplanforNDT,NDTproceduresanddocumentsforNDTinspectors’certificationforacceptancebythepurchaser.Theprogrammeshallcontaininformationanddocumentsforplanning,controlling,reportingetc.AcceptancecriteriaforNDTshallbeacceptedbythepurchaseriftheyarenotspecifiedinrelevantdocuments.VersionSlide2411May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Inspection.Tobecarriedoutinaccordancewithacceptedinspectionandtestplanscovering:correctidentificationanddocumentationanduseofmaterialsqualificationandacceptanceoffabricationproceduresandpersonnelinspectionofpreparatorywork(assembly,fit-upformwork,reinforcementetc.)weldinginspectioninspectionoffabricationworkforcompliancewithspecificationsandprocedureswitnessingNDT,controlandtestinginspectionofrepairsVersionSlide2511May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”inspectionofcorrosionprotectionsystemsensurefunctionalityofexaminationortestingequipmentandofrecordingand/ormeasuringdevicesvitalforcorrectfunctioningofequipmentandmachineryusedinfabrication.Dueconsiderationshallbegiventotheaccessandthetimerequiredforadequateinspectionduringfabrication.Highnon-conformanceratesinexecutionoftheworkorintheproductitselfshallcallforspecialconsiderations.Suchspecialconsiderationsmayinclude,butnotbelimitedto,increasedinspection,re-qualificationofpersonnelorotheragreedremedialactions.NOTE!!Inspectorsshallbequalifiedaccordingtoarecognizedschemeandshallbeabletoprovidedocumentationofproficiency.VersionSlide2611May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”MaterialIdentification,CuttingandFormingMaterialidentificationAtraceabilitysystemthatensurescorrectinstallationanddocumentationofthematerialgradesorstrengthclassesshallbeestablishedbythecontractorthroughouttheprefabricationandinstallationprocess.Propercareshallbeexercisedduringhandlingandstoragetopreserveidentificationofsuchmaterial.VersionSlide2711May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Cuttingandforming.Theeffectofworkhardeningshallbeconsideredifshearingisusedforcuttingofmaterial.Specialattentionshallbepaidtotheriskofcrackededges.Attentionshallbepaidtoexcessivelocalhardeningandcarboncontaminationsbythermalcutting.Thismaybereducedbysuitableheattreatmentorremovedbymechanicalmeans.Formingandstraighteningofmaterialsshallbeperformedaccordingtoagreedprocedures.Suchworkshallbecontrolledbythecontractor.Thedegreeofcolddeformationofspecialandprimarystructuralelementsshallbelessthan5%.Ifthedeformationexceeds5%,eitherheattreatmentorstrainageingtestsshallbecarriedoutaccordingtoanagreedprocedure.VersionSlide2811May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”TolerancesAllowablefabricationtolerancesshallbesubmittedtothepurchaserforacceptance.Specialconsiderationsshallbegiveninprovidingproperalignmentofstructuralmembers.Allowablefabricationtolerancesshallbeestablishedonbasisofdueconsiderationtothecriticalityofthedesign.ThemaximumfabricationtolerancesmaygenerallybetakenincompliancewithIACSShipbuildingandRepairQualityStandardPartASec.6andSec.7.NOTE!!StraightnessofmemberswhicharebasedonbucklingcalculationsaccordingtoDNV-RP-C201and/orDNV-RPC202shallbewithinthetolerancesgiveninTableE3.106Alignmentsofthenon-continuousplatesincruciformjointsandbuttweldsshallbewithinthetolerancesgiveninFig.1,TableE1andTableE2.VersionSlide2911May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”VersionSlide3011May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”VersionSlide3111May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Assembly,Welding,HeattreatmentandRepairsAssemblyandWelding.Assemblyandweldingoperationsshallbecarriedoutbyqualifiedpersonnelandsupervision.Afabricationsequenceshallbeestablishedtoensurethatthestructurecanbeassembledinamannerwhichallowsforeffectivecontrolatallstagesofwork.Fit-up,preparationforweldingandweldingoperationsshalltakeplaceinaccordancewithproceduresacceptedbythepurchaser.Theweldingsequenceshallbesuchthattheamountofshrinkage,distortionsandresidualstressesareminimized.VersionSlide3211May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Thefit-upshallbecheckedfordimensionalaccuracybeforewelding.Surfacestobeweldedshallbefreefrommillscale,slag,rust,grease,paintetc.Edgesaretohaveasmoothanduniformsurface.Noweldingshallbeperformedwhenthesurfacesaredamp.Suitableprotectionshallbearrangedwhenweldingisperformedduringinclementweatherconditions.Thegrooveshallbedryatthetimeofwelding.Preheatingshallpreferablybeperformedwithelectricheatingelements.Gasburnersmaybeusedundercontrolledconditions.Cuttingtorchesshouldnotbeused.Forweldsofstructuralcategoryspecial,primaryandbutt-weldsinsecondarystructuralelementsaWPSshallbeestablishedforacceptancebythepurchaser.VersionSlide3311May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Guidancenote:Theweldconnectionbetweentwocomponentsshallbeassignedthestructuralcategoryareaequaltothehighercategoryofthejoinedcomponents.Forstiffenedplatesnotclassifiedasstructuralcategoryspecial,theweldconnectionbetweenstiffenerandstringerandgirderwebtoplatemaynormallybeassignedstructuralcategorysecondary.Tackweldingshall,whenintegratedinproductionwelding,bequalified.Forweldsspecifiedin112aWPSshallbesubmittedtothepurchaserforacceptance.Allfabricationweldingshallbeperformedwithinthelimitsofessentialvariablesofthequalifiedweldingprocedure.Thisalsoincludestackwelding,sealwelding,weldingofliftinglugsandattachmentweldsaswellasrepairwelding.VersionSlide3411May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Whenresumingweldingonpartiallyfilledjointsinspecialareas,preheatingshallbeperformedandthetemperaturewithinthespecifiedtolerances,shallifnototherwiseagreed,beequaltotheinterpasstemperaturefortheweldingpassinquestion.Groovesproducedbygougingshallbefollowedbygrindingremovingcarbonizedmaterialandthegrooveshallbedressedtoashapeconsistentwithtolerancesinagreementwiththepurchaser.Weldingconsumablesshallbeclassifiedwithrespecttostrength,applicationareaandhydrogenlevelaccordingtorecognizedscheme.VersionSlide3511May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Recyclingoffluxesforsubmerged-arcweldingshallbeperformedinamannerthatensuresamixtureofnewandusedfluxwithcontinuallyhomogenousproperties.Weldsshallbeterminatedinamannerthatwillensuresoundweldswithoutend-craters.Extensionbarsandrun-offplatesshallberemoveduponcompletionandcoolingoftheweld.Theendoftheweldshallbemadesmoothandflushwiththeedgesofabuttingparts.121Grindingofweldswiththeintentionofincreasingthefatiguelifeand/orreducingtheprobabilityofbrittlefractureshallbecarriedoutaccordingtoagreedspecifications.VersionSlide3611May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Storageandhandlingofweldingconsumablesshallbeinaccordancewiththemanufacturer'srecommendations,andinaccordancewithproceduresgivingdetailsregardingconditionsinstoragerooms,temperatureinstorageovensandquivers,lengthofexposureandconditions,asapplicable.Weldingproductiontestsshallbemadeduringfabricationofweldsinspecialareasandinprimarystructuralelementstoverifythattheproducedweldsareofacceptablequality.Minimumonetestcouponisrequiredfromeachappliedweldingprocess.Importantweldingoperationsshallbecarriedoutunderdailysupervisionofaninspector,whohastheexperienceandqualifications,whichenablehimtojudgethistypeofwork.Theworkofeachweldershallberegularlyexamined.Theweldingshopandcontractorsshallkeepacardindexorregisterofallapprovedwelders,withallrelevantinformationregardingqualificationtests,basemetal,consumables,weldpositions,jointdesignetc.VersionSlide3711May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Repairs.Repairsshallbecarriedoutinaccordancewithqualifiedrepairproceduressubjecttoagreement.GuidancetorepairworkmaybefoundinIACSShipbuildingandrepairQualityStandard,PartASec.9andPartB.Membersdistortedbyweldingmaybestraightenedbymechanicalmeansorbycarefullysupervisedapplicationofalimitedamountoflocalizedheat.Theapplicationofheatormechanicalforceshallbeinaccordancewithawrittenprocedure.Defectsinweldsmayberectifiedbygrinding,machiningorwelding.Weldsofinsufficientstrength,ductilityornotchtoughnessshallbecompletelyremovedpriortorepair.Themechanicalpropertiesofrepairweldshallsatisfytheminimumspecifiedpropertiesofthesteelinquestion.VersionSlide3811May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Repairweldinginthesameareamaybecarriedouttwice.Furtherrepairsshallbeevaluatedineachindividualcase.Wheneveradefectisremoved,thegougedandgroundareashallbeexaminedbymagneticparticletestingorothersuitablemethodstoverifycompleteremovalThepreheatingandworkingtemperatureshallwhenmakingshallowandlocalrepairsinspecialandprimarystructuralelementsberaised50oCabovethelevelspecifiedforproductionweldingandbeatleast100oCunlessotherwiseagreed.Forplanardefectstherepairlengthoneithersideofthedefectshallbe50mmlongerthanthesizeofthedefectasconfirmedbyNDTToensuresoundrepairwelds,thesinglerepairlengthshallnotbeshorterthan50mm.VersionSlide3911May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Minordiscontinuitiesmayberemovedbygrindingormachining,makingasmoothtransitionintothesurroundingmaterial.Thethicknessshallnotbereducedtolessthan93%ofthenominalthicknessbutinnocasebymorethan3mm.Theextentofsuchrepairshallbeagreedupon.Allrepairsshallbere-inspectedwiththesameNDTmethodstothesameorincreasedextentasnecessary.VersionSlide4011May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Non-DestructiveTesting.GeneralPriortocommencementoffabricationthecontractorshallsubmitaplanforNDT,NDTproceduresanddocumentsforNDTinspectors’certificationforacceptancebythepurchaser.Theprogramshallcontaininformationanddocumentsforplanning,controllingandreporting.TheinspectioncategoriesshallbedefinedinaccordancewithDNV-OS-C101Sec.4orDNV-OS-C201Sec4andshallbespecifiedinrelevantdesigndrawings.WeldsshallbesubjecttoNDTinprogresswithfabrication.Theresultsoftheseactivitiesshallbeconsecutivelyreportedtothepurchaser.VersionSlide4111May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”MethodsofNDTshallbechosenwithdueregardtotheconditionsincludingthesensitivityofthemethodandthemethod’sabilitytodetectdefectslikelytooccurasaconsequenceofthechosenweldingprocess.FinalinspectionandNDTofstructuralsteelweldsshallnotbecarriedoutbefore48hoursaftercompletion,exceptwherePWHTisrequired.ThetimedelaymayuponagreementbereducedforNV36gradesorlowerandforNV420gradesorlowerforplatethicknesseslessthan40mm,ifconsistentlowfailurerateofdelayedcrackinghasbeendocumentedforthematerialsandweldingconsumablesinquestion.VersionSlide4211May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Whenheattreatmentisperformed,thefinalNDTshallbecarriedoutwhenallheattreatmentshavebeencompleted.Allweldsshallbe100%visuallyinspectedpriortocarryingoutNDT.AllNDTshallbeproperlydocumentedinsuchawaythattheperformedexaminationcanbeduplicated.Thereportsshallidentifythedefectspresentintheweldareaandstateiftheweldsatisfiestheacceptancecriteriaornot.VersionSlide4311May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”NDTProceduresNDTshallbeperformedinaccordancewithagreedwrittenproceduresthat,asaminimum,givedetailedinformationonthefollowingaspects:applicablecodeorstandardmaterialsanddimensionsweldingprocessjointconfigurationanddimensionstechniqueequipment,mainandauxiliarysensitivityVersionSlide4411May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”calibrationtechniquesandcalibrationreferencestestingparametersandvariablesassessmentofimperfectionsreportinganddocumentationofresultsreferencetoapplicableweldingprocedure(s)personnelqualificationacceptancecriteria.VersionSlide4511May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”PersonnelqualificationPersonnelperformingNDTandinterpretationofexaminationresultsshallbecertifiedaccordingtoarecognizedcertificationschemesubjecttoagreementandshallprovideavalidcertificateofproficiency.Thecertificateshallstatethequalificationsastowhichexaminationmethodandwithinwhichcategorytheoperatorisqualified.NOTE!!ThisrequirementisalsovalidforVisualinspectorsasvisualinspectionisthefirst,andmaybethemostimportantstepofNDTinspectionVersionSlide4611May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”ExtentofNDTExtentofNDTshallbebasedontypeandlevelofdesignstressesandontheimportanceoftheconnectioninquestion.Theweldsshallbeassignedinspectioncategoriesequaltothehigheststructuralcategoryofthetwocomponents.Forstiffenedplates,whicharenotassignedInspectioncategoryI,theweldconnectionbetweenstiffenerandstringerandgirderwebtotheplatemaynormallybeinspectedaccordingtoInspectionCategoryIII.Radiographicexaminationmaybereplacedbyultrasonicexaminationandviceversa,whenmethodologicallyjustifiableandinagreementwiththepurchaser.FrequentrepairsshallresultinincreasedextentofNDT.VersionSlide4711May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”NDTshallnormallybecarriedouttoanextentnotlessthanrequiredinTableB1.VersionSlide4811May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”AcceptancecriteriaforNDTVersionSlide4911May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”VersionSlide5011May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”VersionSlide5111May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”O(jiān)thertestsTightnesstestAlltankstobetestedfortightness,eitherbywaterorcompressedairandefficientindicatingliquid.Tightnesstestwithairshallbecarriedoutbeforeprotectivecoatingisapplied.Maxairpressurenottoexceed20kN/m2,andtobereducedtomin.15kN/m2beforetestcommences.Min.waterpressureto25kN.m2atthetopofthetank.Theoutsideofthetanktobedryandcleanwhenwatertestingisapplied.VersionSlide5211May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”StructuralTestAtleastoneofidenticaltankstobestructurallytestedbywaterpressureifnototherwiseagreed.Bulkheadsbetweentanksarrangedtocarrydifferentliquidsshallbehydraulicallytestedatleastfromoneside.Pressuretobemaintainedatleast20min.Nosignificantdeformationsorotherdamagestooccurasaresultofthetesting.Ifstructuraltestrevealweaknessesinthestructure,furthertestingshouldbeassessed.VersionSlide5311May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Productiontests.Atleastoneweldingproductionshallbemadeduringfabricationofweldsinspeciqalareaandinprimarystructuralelementstoverifythattheproducedweldsareofacceptablequality.Minimumonetestcouponisrequiredfromeachappliedweldingprocess.VersionSlide5411May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”Coating.Thesurfacestobecoatedshallbecleananddry.Oil,greaseordirtshallberemovedbywashingwithasuitabledetergent.Saltsshallberemovedbywashingwithfreshwater.Sharpedgesshallberoundedandsurfacesblast-cleanedtotheprofileanddegreeofcleanlinessasrequiredinthecoatingspecificationandinaccordancewiththecoatingmanufacturer’srecommendations.Normally,theminimumrequirementsforsteelsurfacequalityforprimercoatingapplicationisISO8501-1Sa21/2orequivalentforexternalsurfacesandinternalzonesexposedtosea-waterorotherwiseintendedforcoating.Finalblast-cleaningandcoatingapplicationshallwhenpossiblebecarriedoutonlywhenthesteeltemperatureis>3°Cabovethedewpointandtherelativehumidity<85%inordertopreventcondensationofmoistureonthesurface.VersionSlide5511May2023DNV-OS-C401”FabricationandTestingofOffshoreStructures”SacrificialanodesAnodeshapesandtheirfasteningdevices(studs,clamps,etc.)shallbesubjecttoagreementwiththepurchaser.Foranodesfastenedbyothermeansthanwelding,attentionshouldbepaidtotheestablishingofgoodelectricalcontact.Resistancemeasurementsmayberequired.Weldingofconnectionsshallbecarriedouttoproceduresacceptedbythepurchaserandbyqualifiedwelders.Anodesshallifnototherwiseagreed,beconnectedto